Most shot timers, (mine anyway) has the start buzzard going off at radom times, meaning you don't know when they are going off.
What the OP is talking about is more then doable.............like any thing else, it just takes practice.
I practice drawing my 642 from my pocket all the time, there is nothing unreasonable about the times posted by the OP.
My best time was .43, most are a bit slower then that.
That of course is starting with my hand in the pocket gripping the revolver.
But I normally walk around with my hands in my pocket anyway and do most of my pocket revolver one handed.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071